5results about How to "Improve cycle retention" patented technology

The invention provides an organic-inorganic hybrid solid-state polymer electrolyte coated high-nickel positive electrode material as well as a preparation method and application thereof, and relates to the technical field of all-solid-state lithium batteries. The high-nickel positive electrode material coated with the organic-inorganic hybrid solid polymer electrolyte comprises an inner core and an organic-inorganic hybrid coating layer coated on the surface of the inner core, the inner core is made of a high-nickel positive electrode material; the organic-inorganic hybrid coating layer comprises a ring-opening copolymer of maleic anhydride and 1, 3-dioxolame, and Li3PO4 nanocrystals are embedded into the ring-opening copolymer of maleic anhydride and 1, 3-dioxolame in situ. According to the invention, a flexible and compact coating layer with ionic conductivity is constructed on the surface of the high-nickel positive electrode material, so that the problems of violent interface side reaction, large interface impedance and poor cycling stability existing between the high-nickel positive electrode material and sulfide solid electrolyte are solved; therefore, the electrochemical performance of the material in a sulfide all-solid-state lithium battery is remarkably improved.

The invention discloses a ternary material precursor, a ternary material and a preparation method, and belongs to the field of lithium ion battery positive electrode materials. The ternary material precursor is of a multi-layer composite structure and sequentially comprises a core layer, a first transition layer and a second transition layer from inside to outside, and all the layers are prepared by adopting the same ternary (nickel-cobalt-aluminum) system. Through reasonable design of the proportion and thickness of the ternary system of the core layer and the transition layer, the ternary material precursor gives consideration to the high-capacity characteristic of the high-nickel core and the stability of the shell, and the stable structure of the shell can effectively inhibit the structural change and interface side reaction of the high-nickel material in the charging and discharging process. The phenomena of particle cracking and shell layer falling are reduced, and the material shows excellent specific discharge capacity, good cycle performance and thermal stability when being used as a lithium ion battery positive electrode material.

This invention provides a lithium cobalt oxide cathode material coated with a lithium aluminum titanium phosphate composite, which has a core-shell structure, comprising a doped lithium cobalt oxide core material inside the core-shell structure and a coating layer formed on the surface of the doped lithium cobalt oxide core material; the chemical formula of the doped lithium cobalt oxide core material is: LiCo 1‑a‑b‑c Mg a Al b Ce c The coating layer comprises lithium aluminum titanium phosphate, cerium titanate, lithium cerium phosphate oxide, and lithium cerium phosphate. This invention's lithium aluminum titanium phosphate composite coating modified lithium cobalt oxide cathode material overcomes the defect of a sharp performance drop under high temperature and high pressure applications when lithium aluminum titanium phosphate is coated alone. The oxygen vacancies and coating structure provided by the composite coating layer of lithium aluminum titanium phosphate, cerium titanate, lithium cerium phosphate oxide, and lithium cerium phosphate enhance the structural continuity between the bulk phase and the coating layer, as well as the conductivity of the fast ion conductor, thereby enabling the material to maintain good cycle retention and capacity characteristics under high temperature and high pressure.

The application provides a method for preparing a silicon-carbon material from photovoltaic waste silicon, comprising the following steps: S1, disassembling and cutting a decommissioned crystalline silicon photovoltaic panel to obtain a photovoltaic module; S2, soaking the photovoltaic module in an organic solvent to perform a degumming treatment, and peeling to obtain a silicon wafer; the organic solvent comprises at least one of terpinolene, terpineol, ethanol and polyvinylpyrrolidone; S3, performing ball milling and acid immersion treatment on the silicon wafer to obtain a silicon material; S4, mixing the silicon material with a carbon source material, and performing carbonization treatment to obtain a carbon-silicon material; S5, mixing the carbon-silicon material with raw materials for preparing an inorganic lithium salt, performing ball milling and calcination to obtain a modified carbon-silicon material; the raw materials for preparing the inorganic lithium salt comprise a lithium source and an anion source. The silicon wafer is peeled off efficiently and environmentally, then the carbon-silicon material is obtained by carbonization of the carbon source, and the surface of the carbon-silicon material is modified by in-situ construction of an inorganic lithium salt coating layer, so that the obtained electrode material has a high cycle retention rate.

The invention discloses a preparation method for preparing a ternary material by using a nickel-iron alloy and the ternary material, and belongs to the technical field of ternary material preparation, and the preparation method comprises the following steps: S1, carrying out crushing and roasting pretreatment on the nickel-iron alloy, then carrying out acid leaching in a sulfuric acid solution, and filtering and collecting a mixed solution; s2, sequentially adding a sodium sulfide solution and a sodium fluoride solution into the mixed solution, filtering, and collecting a refined solution; s3, supplementing a cobalt source and a manganese source into the refined solution, and adjusting the molar ratio of Ni < 2 + > to Co < 2 + > to Mn < 2 + > in the solution to be x: y: (1-x-y), x = 0.6-0.8, and y = 0.1-0.2; adjusting the pH value of the refined solution to 10.5-11.5, filtering and collecting a precipitate to obtain a ternary precursor; and S4, uniformly mixing the ternary precursor, a lithium source and a doping agent to obtain a mixture which is yttrium salt and zirconium salt, and sintering the mixture to obtain the ternary material.